In the related art, there has been an optical information reader (two-dimensional code reader) that includes a capturing unit which has a two-dimensional capturing field and captures an image of a reading target containing an information code, and a marker-beam irradiating unit which irradiates the reading target with a marker beam so as to mark a reading position on the reading target.
The optical information reader (two-dimensional code reader) includes an approach-detecting unit that detects a relative approach of the information code into the capturing field of the capturing unit, and a reading-operation executing unit that causes the capturing unit to automatically execute a reading operation of the information code, based on the detection by the approach-detecting unit.
The approach-detecting unit has a marker-beam image acquiring unit that captures an image of a reading target by the capturing unit in a state of the irradiation with the marker beam by the marker-beam irradiating unit, and a brightness-pattern detecting unit that detects a brightness pattern in a marker-beam irradiated portion on a marker-beam image captured by the marker-beam image acquiring unit. The approach-detecting unit further has a judgment unit that judges the approach of the information code into the capturing field, based on a change in the brightness pattern in marker-beam images acquired at different timings.
The optical information reader (two-dimensional code reader) has a control circuit that executes a reading control program such that a marker-beam irradiating portion continually performs irradiation (turning-on) with the marker beam (or repeats turning on and off) when power turns on.
The control circuit continuously monitors whether or not the two-dimensional code contained in the reading target relatively approaches the capturing field (reading position marked by the marker beam) of a beam-receiving sensor, and automatically executes the reading operation (operation in which an illumination unit turns on and an image is captured by the beam-receiving sensor 13) of the two-dimensional code when the approach is detected. Japanese Laid-open Patent Publication No. 2006-134303 is known as an example of the related art (see, for example, claim 1 and paragraph [0032] in the specification).
In the optical information reader (two-dimensional code reader) in the related art, the control circuit, which executes the reading control program, automatically executes the irradiation with the marker beam, monitoring of the two-dimensional code, and a reading operation of the two-dimensional code.
Incidentally, the optical information reader (two-dimensional code reader) in the related art does not succeed every time in reading of the two-dimensional code, and, sometimes, the two-dimensional code is not read. However, the control circuit automatically executes such control described above, when the power turns on.
Since the control circuit, which executes the reading control program, is executed by a computer, power consumption is increased. For example, even in a case where the two-dimensional code is not read, power consumption is increased by performing a process of an access to a memory or the like.